With development of long term evolution (Long Term Evolution, hereinafter briefly referred to as LTE), an LTE system and a universal mobile telecommunications system (Universal Mobile Telecommunications System, hereinafter briefly referred to as UMTS) will coexist on a network. In the UMTS-LTE hybrid networking scenario, the LTE system and the UMTS may be used together to transmit user services, thereby improving a transmission rate.
In a UMTS-LTE resource convergence (UMTS LTE Boosting, hereinafter briefly referred to as UL Boosting) scenario that has a base station (evolved NodeB, hereinafter briefly referred to as eNB) as an anchor point, the LTE system remains unchanged, and a radio network controller (Radio Network Controller, hereinafter briefly referred to as RNC) of an access network node on the UMTS accesses a core network of the LTE system by using an eNB. In this scenario, an access network of the UMTS and an access network of the LTE system exist but a core network of only the LTE system exists. A user equipment (User Equipment, hereinafter briefly referred to as UE) may transfer data to the core network by using network elements on the access networks of both the UMTS and the LTE system at the same time, thereby improving a service transmission rate.
In a UL Boosting scenario that has an eNB as an anchor point, an RNC and an eNB reserve current protocols in a relatively complete manner/to a great extent, and data of the LTE system and data of the UMTS converge at a packet data convergence protocol (Packet Data Convergence Protocol, hereinafter briefly referred to as PDCP) layer. In the prior art, the LTE system and the UMTS perform security protection on service data by using their own security protocol layer.
However, in a UL Boosting scenario that has an eNB as an anchor point, a UE performs an authentication and key agreement (Authentication and Key Agreement, hereinafter briefly referred to as AKA) with a core network through the LTE system and generates a key to the LTE system. But, in the UL Boosting scenario that has an eNB as an anchor point, only an access network of the UMTS exists and a core network of the UMTS does not exist. Therefore, the UMTS cannot perform authentication with the core network to generate a key to the UMTS. If the UMTS does not have a security key, data transmitted in the UMTS is not protected for security and is easily to be intercepted by attackers, thereby having low security.